Can someone explain chances of 4 kids with blue eyes when one parent is brown eyed?

https://www.allaboutvision.com/eye-care/eye-anatomy/eye-color-genetics/

2 of my nephew's were born with blue eyes but within a week or 2 their eyes had somehow turned to brown. My sister said one DC went to sleep with blue eyes one morning and by dinner time his eyes were light brown. The next day they had turned darker brown. It's amazing.

The odds of any one child having blue eyes are also completely independent from the eye colours of the other children. Each child has the same odds.

If one parent has blue eyes then yes it is 50/50.

We both have brown eyes, both DDs have blue eyes. I was very surprised by this x

Genetics are a crazy thing. My aunt and uncle are both average heights (5ft 6 and 5ft 10) with straight brown hair and green eyes.
Child one: 6ft 5 brown hair, green eyes, child two: 6ft curly ginger hair, blue eyes,
Child three: 5ft 1 blond hair, green eyes
Child four: 5ft 5 Black hair, brown eyes
Child five: 6ft 2 curly blond-brown hair, brown eyes.

Punjabi people have mixed heritage as there have been various groups in the region, notably Alexander the Great conquered the region (and his army seem to have left their genetic heritage!)

I am Punjabi myself and have a large family (many are very white & green eyed despite 100% Punjabi origins).

I also know many mixed Punjabi/White families. Blue eyes and very white skin not very unusual for mixed Punjabi/Caucasian kids (4 in same family less usual) : sometimes this changes as kids grow older too

Me brown eyes , DH blue, both sons blue , I also thought brown would ‘win’

No, I know. But it’s a simple way to explain why someone with brown eyes might carry a blue gene.

Perfectly possible. My DD has blue eyes - she is white / Asian. DS has brown eyes.

Brown, hazel eyes are pigments in the iris.
But blue/ green/ grey have almost no pigment. The colour comes mostly from how the iris reflects light around.
The pigment is actually melanin, so brown in itself.
We all know people whose eye colour changes with the lighting conditions.
Also, it is common for people that genetically should have green eyes to appear brown, or even change colour through life, have a green/ brown combination in the eyes.

I’m ginger with brown eyes, DH is brunette with blue eyes.
We have 1 brunette with hazel eyes, 1 brunette with blue eyes and 1 blond with grey/blue eyes.

Your BIL has a green/ blue eyes gene and one dark brown.
Your DS two blue eyes genes.
Chances are then 50% for blue and 50% dark brown for each child.
They just happened to have all kids in the blue lot.

I have blue eyes husband has brown we have 4 kids 3 with blue eyes but all different types of blue and one with brown eyes..

I asked this. Apparently the BB Bb bb recessive dominant etc. is the equivalent of telling a GCSE kid that a cell is a nucleus, cytoplasm and a cell membrane.

In actual fact that’s a complete lie. There’s a lot of shit in a cell. And apparently eye colour is way more complicated than that.

My parents are (dusky grey) blue and green also. My sisters brown and I am dark blue with an orange strike through one.

My partners almond brown. My little boys eyes are almost jet black.

The likelihood is 50/50 each and every time, so each child has a 50/50 chance of blue eyes.

I've got 4 boys.
One blue eyed, 3 brown.
I've got blue eyes, my husband has brown.

I'm also one of 4.
All of us have blue eyes, my mam has blue eyes and my dad has brown

Exactly the same chance of them four girls or four boys.

I'm from a similar background to your BIL. I have medium brown eyes, my (Caucasian ) husband has blue eyes. Husband's dad (Caucasian) has blue eyes. Our son has blue eyes. Mother in law (Caucasian) has dark brown eyes. My daughter has dark brown eyes. My mum (Punjabi) has dark brown eyes. My dad (Punjabi) has greyish eyes. I think my dad's mum also had greyish eyes. It's complicated.

I have green eyes - a different shade to my mum. Dad has brown. His parents had brown and blue eyes.

Think my mum got green eyes from her father. She has no memory of him as he died when she was 4. Her father was 8-10 years older than his MIL. I certainly remember that my grandmother had blue eyes.

My green eyes are unusual. Smoky grey outer with brown flecks around iris. Maybe pretty to look at but looking through them - different story

Im an only child and if I had siblings they would have different colours eyes

I'm a ghost pale, green eyed, bright redhead

Mum is dark olive skin, dark brown eyes, almost black hair. So is the rest of the family on her side, they step outside and tan very dark
Dad is average skin tone, blue eyes, strawberry blonde

I look like a randomer that's dropped in for tea at any family gatherings

I've got two with brown eyes and brown hair, one with greeny brown eyes and brown hair and one blonde with blue eyes. Parents are both brunette, one with brown eyes and one with blue. I love the differences :-)

From what I've read apparently blue is the weaker colour? My parents have a mix of blue and Hazel eyes and we have green. A friend is mixed race, predominantly Pakistani and her partner Caucasian and their kids have blonde hair and blue eyes. Another friend is Swedish, DH mixed race, predominantly Moraccon, and their kids have darker skin and brown eyes. Yes, genetics are interesting and go way back. Doesn't seem to matter what gender, present physical attributes, the strongest gene comes through? So the studies which say blue eyes are weaker are being disproven. Xx

This isn’t how eye colour genetics works though, as explained by @KrisAkabusi

It’s not as simple as brown trumps blue.

I have three girls all blue eyed. Their Dad and I both have hazel / brown eyes but we both have parents with blue eyes